What does the Andromeda and Milky Way distribution look like?: Two main- and multiple secondary arms by multiple Herbig Haro Black Hole mergers.(see: Q_FFF model)
see: Primordial Black Holes and Dual Herbig Haro Effects for Star-Galaxy Formation see: https://vixra.org/pdf/2101.0158v1.pdf
and: https://bigbang-entanglement.blogspot.com/